05000254/FIN-2009004-02
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Finding | |
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| Title | Adequacy of 10 CFR 50.59 Evaluation and Dose Consequence Assessment for Catastrophic Fire in the Interim Radwaste Storage Facility |
| Description | The inspectors identified that the licensee stored radioactive waste (radwaste) in its IRSF in forms other than as evaluated in the current facility Fire Hazard Analysis Report. The fire hazard analysis provided the fire protection assessment for the IRSF as part of the licensee\'s 10 CFR 50.59 evaluation for the facility. As a result, the inspectors identified an unresolved item (URI) for the apparent failure to complete a 10 CFR 50.59 evaluation to assess the radiological consequences of a design basis fire consistent with the manner in which processed waste was currently stored in the IRSF. The IRS was constructed in the 1980s to store processed radioactive waste for short time periods incident to disposal at a low-level waste repository or for extended storage should disposal sites be unavailable. Capacity of the IRSF allows for over 400 liners (195 cubic feet/liner) containing an approximate aggregate 20,000 curies of radioactive waste to be stored. Since the 1990s, waste storage in the Quad Cities IRSF was limited, as low-level waste disposal sites were available and routinely utilized. Typically, no more than approximately ten liners of processed radwaste were stored at any given time in the IRSF. In mid-2008, the South Carolina Barnwell disposal site ceased accepting waste from most waste generators so options for disposal of Class B and C waste no longer existed for the Quad Cities station. In September 2009, the Quad Cities IRSF stored more than 50 liners of processed radwaste in the form of dewatered resin housed in polyethylene high integrity containers (poly HICs). The Fire Hazard Analysis Report for the IRSF completed in July 1992 assumed the facility housed 200 containers of processed radwaste that was solidified or encapsulated in concrete and stored in poly HICs. The radiological consequences of a catastrophic facility fire was calculated on the basis that dose at the exclusion area boundary resulted from heat induced fracture of the concrete inside the HICs, generating airborne radioactive particulates. The dose calculated on that basis determined that the dose to the public was about 1.2 percent of the 10 CFR 100 limit. A fire suppression system was not installed in the IRSF based, in part, on the results of that calculation. The bases for the 1992 calculation, however, has been inconsistent with the licensee\'s radwaste processing practices since the early to mid-1990s, when the licensee discontinued solidifying its processed waste. A bounding calculation performed by the licensee following the identification of this issue during this inspection determined that the radiological consequence of a catastrophic fire in the IRSF (using the actual radioactive source term present in the facility in September 2009, and conservatively assuming 100 percent release to the environment) was approximately 6 percent of the 10 CFR 100 dose guideline. The bounding calculation yielded a dose approximately five times greater than the dose calculated assuming partial release of radwaste to the environment from concrete fracture yet was based on a smaller radiological source term. The issue remains under review by the NRC pending completion of the licensee\'s revised 10 CFR 50.59 evaluation and associated 10 CFR 100 catastrophic fire dose consequence assessments, consistent with current waste forms/storage methods. The issue is categorized as a URI pending completion of that revised evaluation and the subsequent NRC review (URI 05000254/2009004-02, 05000265/2009004-02) |
| Site: | Quad Cities  |
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| Report | IR 05000254/2009004 Section 2PS2 |
| Date counted | Sep 30, 2009 (2009Q3) |
| Type: | URI: |
| cornerstone | Pr Safety |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71122.02 |
| Inspectors (proximate) | R Jickling M Mitchell B Palagi M Ring J Mcghee B Cushman J Draper M Learn C Mathewsc Matthewsw Slawinski M Ring J Benjamin J Mcghee B Cushman |
| INPO aspect | |
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Finding - Quad Cities - IR 05000254/2009004 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Quad Cities) @ 2009Q3
Self-Identified List (Quad Cities)
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